Forged or Cast

[buzzard]

More of a peak cylinder pressure too early problem.

Chris

[col]

That is what I was getting at by refering to the timing. But yes if the peak pressure is too early, you are just pushing backwards compressing the rod. That is the best way to break them.Too much timing won't make extra hp just smash your engine, not to mention detonation.
Peak cylinder pressure should be as late as possible between 15 and 25 deg after tdc.
Peak should also be as long as possible , that is why I like water injection.

[Mx5 nut]

Originally Posted by col

That is what I was getting at by refering to the timing. But yes if the peak pressure is too early, you are just pushing backwards compressing the rod. That is the best way to break them.Too much timing won't make extra hp just smash your engine, not to mention detonation.
Peak cylinder pressure should be as late as possible between 15 and 25 deg after tdc.
Peak should also be as long as possible , that is why I like water injection.

I never found waterinjection to work as well as a well tuned Engine
Yes peak Pressure is Up with 18 PSI of boost but the Rods ARE a week point in these engines and with beter rods and a little bit of head work I made 245KW@RW at 5000 rpm on 14PSI but had a mis fire problem so have to go back to the Dyno when I findthe PROB
Still happy with results

[Shannon]

OK people have different sides of the fence to sit on.
I supposed that the thing is that if you can afford it then go forged, if you can't go cast and keep things at a limit that is not going to cause problems, (maybe, hopefully,)
I suppose the question that I was asking was, because that there is less air going in, would it be worth it. less air, smaller bang
But as some body said sorry can't remember who, because of the restrictor then you try and get as much boost as possible so I looks like that's the answer.
Go Forged
Now how much more is a set of forged pistons over cast ?

[col]

I think the question is ;
How much hp are you looking for?
That answer will let you know what you need. Under 200hp to 250hp and 7000rpm ,use cast and standard rods. Tuned well you can use it all day long.
In a mx5 on dirt that is a heap of hp and you would need to be a hell of a driver to make use of more. I would lean towards the 200hp spend more money on suspension.

[Mx5 nut]

Originally Posted by Shannon

OK people have different sides of the fence to sit on.
I supposed that the thing is that if you can afford it then go forged, if you can't go cast and keep things at a limit that is not going to cause problems, (maybe, hopefully,)
I suppose the question that I was asking was, because that there is less air going in, would it be worth it. less air, smaller bang
But as some body said sorry can't remember who, because of the restrictor then you try and get as much boost as possible so I looks like that's the answer.
Go Forged
Now how much more is a set of forged pistons over cast ?

Try Hear http://www.belfabracing.com/product_...f233be9a0783f2
and
http://www.belfabracing.com/product_...f233be9a0783f2

[Mx5 nut]

Originally Posted by col

I think the question is ;
How much hp are you looking for?
That answer will let you know what you need. Under 200hp to 250hp and 7000rpm ,use cast and standard rods. Tuned well you can use it all day long.
In a mx5 on dirt that is a heap of hp and you would need to be a hell of a driver to make use of more. I would lean towards the 200hp spend more money on suspension.

Are you Talking at the Flywheel or REAR Wheels?

[col]

Talking engine hp.

[Spac]

The car in question is a BF Familia, with B6T, with a PRC restrictor.

[col]

Sorry Shannon I got the wrong opinion on what car it was.
Still restrictor or not , How much hp are you looking for?

[Buerckner]

Originally Posted by Spac

The car in question is a BF Familia, with B6T, with a PRC restrictor.

Also the suspension and brakes are pretty good already. It's a fairly well sorted car and I'd assume the engine rebuild is preventive or because it's a little tired.

[bms]

ive had a bf mr and ive know got a couple of gtr familia s with one i rallied in a few vic rallies last year. The rods aren t the problem on the B6 1.6 there as big as the ones on the BP 1.8 gtr your best off getting a good set of forges from america arias, cp etc the motors are strong as running prc there bullet proof with a good ecu and tune. My bpd 1.8 gtr running motec m4 pro anti lag was putting out 180 atw with prc restrictor before 5500 rpm. With the close ratio albins dog box its like the playing play station !!!! i just gotta get some time to learn how to drive it...

bear

[smee]

All true.
Just got my engine back from the builder (after TNT delivered it to the wrong address) and it should all be good.
The car was running with 2 bent rods, and end caps etc out of place, but still produced good power.
Now has ARP head and rod bolts along with forged rods and wiesco pistons and adj vernier gears.
So should go even better with a good tune.
Just need a better gearbox now.

[RS1800]

End caps out of place? mmmm really? Not sure about that, sure your not being spun a line? How did they fix that particular problem? And if they were out of line, by how much? Seems perculiar to me but I am no "expert"

[Mx5 nut]

Originally Posted by smee

All true.
Just got my engine back from the builder (after TNT delivered it to the wrong address) and it should all be good.
The car was running with 2 bent rods, and end caps etc out of place, but still produced good power.
Now has ARP head and rod bolts along with forged rods and wiesco pistons and adj vernier gears.
So should go even better with a good tune.
Just need a better gearbox now.

I know I Help with advice on that engine .
Also ARP main Studs
Hope it goes well